The primary goal of this research project is the continued development, testing, and refinement of a comprehensive computational modeling framework addressing the neural processes underlying speech perception and production. This framework is defined using adaptive neural networks, allowing comparisons with data from imaging studies of brain function. The proposed research includes five modeling studies and nine closely related functional magnetic resonance imaging (fMRI) experiments to test model predictions. These studies constitute five subprojects to flesh out different aspects of the investigators' modeling framework. The first subproject, modeling and imaging studies of neural map formation in the auditory cortical areas, will extend their earlier studies into the nature of sound categories in the auditory system (e.g., phonemic categories) and the warping of auditory perceptual space evident from phenomena such as categorical perception and the perceptual magnet effect. The second subproject, modeling and imaging studies of visual influences on speech perception, will extend the investigators' earlier work studying the nature of visual influences on speech perception as evidenced by the McGurk effect, and will address learning processes hypothesized to underlie visual-auditory associations. The third subproject, modeling and imaging studies of central aspects of the DIVA model, will address the neural processes underlying the control of speech articulations, including the involvement of the cerebellum in normal subjects and subjects with cerebellar damage, and the effects of auditory and somatosensory feedback perturbations to activations in different brain areas. The fourth subproject, modeling and imaging studies of movement selection, initiation, and sequencing, will address the involvement of the supplementary motor area, anterior cingulate area, and basal ganglia in speech production. In the fifth subproject, a distributed model of cortical and subcortical interactions in speech, the results of earlier projects will be combined into a comprehensive model of the neural processes underlying speech perception and production. The modeling hypotheses have been specifically designed to be testable with existing or easily attainable fMRI techniques. Several new imaging and data analysis techniques will also be investigated to stay abreast of the most effective methods for testing the hypotheses. When appropriate, these techniques will be utilized to improve the experiments.